this is not all that different from what other websites do right now. you are there to shop, after all. you know, think of all the times you are looking for a dress online and then you see the store's ad pop up on another site you were on later in the day and you thought, gosh, how did they know that? all about how they track your shopping online. now, you probably noticed if you're on the amazon site and you're browsing there, a bunch of items pop up that are called recommended for you. you think, oh, wow, i like that. but amazon's recommendation formula is pretty simple because it bases its suggestions on what you bought in the past, which items you have in your shopping cart, the items you rated and what other customers have viewed. so, let's say you're a new parent and you may see suggestions for bottles, diapers and other things for a newborn and sports fans, you know, they may get recommendations for collector's dvds and things like that. it does have an appropriately technical name, as well.